Large area ultraviolet photodetector on surface modified Si:GaN layers

摘要

Graphical abstractDisplay OmittedHighlights•Large area UV photodetector with ZnO microstructures on Si:GaN.•Significant response to UV light.•Higher responsivity (0.96 A/W) and detectivity (∼4.87 × 109Jones).•Tunable functionality of photodetector by modification of the surface morphology.AbstractUnique features of semiconductor based heterostructured photoelectric devices have drawn considerable attention in the recent past. In the present work, large area UV photodetector has been fabricated utilizing interesting Zinc oxide microstructures on etched Si:GaN layers. The surface of Si:GaN layer grown by metal organic chemical vapor deposition method on sapphire has been modified by chemical etching to control the microstructure. The photodetector exhibits response to Ultraviolet light only. Optimum etching of Si:GaN was required to exhibit higher responsivity (0.96 A/W) and detectivity (∼4.87 × 109Jones), the two important parameters for a photodetector. Present method offers a tunable functionality of photodetector through modification of top layer microstructure. A comparison with state of art materials has also been presented.